Study of the Process of Reversible Insertion of Lithium into Nanostructured Materials Based on Germanium

Nanostructured germanium samples prepared by electrochemical deposition from aqueous solution of 0.05 M germanium oxide onto titanium substrate are tested as the negative electrodes of lithium-ion batteries. The reversible capacity in the process of lithium insertion-extraction is found to be about 1180 mA h/g, which corresponds to the formation of Li3.05Ge alloy. The effective diffusion coefficient of lithium in germanium is shown to be 1.2 x 10(-11) cm(2)/s. The degradation of the germanium electrode upon cycling at 0.6 C rate is less than 0.3% per cycle.